Separate regions of the hypothalamus appear to have profound and opposite effects on animals' motivated behavior (e.g., feeding and attack). However, it now appears that these same brain areas can influence animals' basic sensorimotor functions as well. The sensorimotor changes which result for stimulation or destruction of the medial or lateral hypothalamic area contribute to their effects on feeding and attack. It now appears likely that ascending catecholamine-containing neural systems, particularly the nigrostriatal dopamine dundle, are particularly important in mediating the lateral hypothalamic influence over sensorimotor functions. I propose (1) to examine in detail the neural basis for these sensorimorte impairments seen after lateral hypothalamic damage, (2) to pursue their relevance to the changes in motivated behavior apparent after such lesions, and (3) to investigate the neurochemical changes which may underlie the hyperresponsiveness to sensory stimult seen after medial hypothalamic damage.